The event loop allows Node.js to handle multiple operations without blocking the main thread. Imagine a waiter taking multiple orders instead of waiting at one table. Node can handle thousands of requests efficiently because the event loop manages async tasks like I/O operations.
Active Recall
6 Flashcards
Interview Flashcards & Mock Mode
Practice with 3D flip cards, voice reader, and timed interview simulations.
Speed Drills
60s Micro-Tests
CodeShot.in — Daily Challenges
60-second in-browser coding micro-challenges to sharpen syntax and problem-solving speed.
What is the event loop in Node.js and why is it important?
What is Express.js and how is it used in Node.js?
Express.js is a lightweight framework on top of Node.js used to build web servers and REST APIs. Think of Node.js as raw ingredients and Express as a ready-made kitchen setup that lets you cook faster and cleaner.
What is middleware in Express.js?
Middleware is a function that executes between the request and response cycle in Express.js. It can modify requests, responses, or stop the request entirely. It’s like airport security—every request must pass through checks before reaching its destination.
What is error-handling middleware in Express?
Error-handling middleware catches errors centrally and sends consistent error responses. It prevents the app from crashing and improves debugging and user experience.
What is the purpose of package.json in Node.js?
package.json manages project metadata, dependencies, and scripts. It’s like a recipe card—anyone can recreate the same dish by following it.
Why is package-lock.json important?
package-lock.json locks exact dependency versions to ensure the same behavior across environments. It prevents the 'works on my machine' problem.